amirfish1/claude-command-center/a-b-copy

A-B-copy runs a clean copy comparison: two writer sessions get the identical message architecture but different voice constraints, then a third session — a judge who wrote neither draft — scores both against the architecture and reports a winner plus a steal list. It builds on the spawn/report_to mechanics in the ccc-orchestration skill — read that first for the full Spawn/Inject/Ask API.

Cost

3 spawned sessions (2 writers + 1 judge). Each spawn is a real billed session on the user's kanban — tell the user the count before spawning.

Cheaper variant: 2 spawns and you judge — but a judge who wrote neither draft is the point (no authorship bias), so state the tradeoff before dropping it. Not for routine copy tweaks — if you just need one line of copy, write it yourself.

Setup

CCC_URL="$(cat ~/.claude/command-center/port.txt 2>/dev/null || echo "${CCC_URL:-http://127.0.0.1:8090}")"
curl -sf --max-time 2 "$CCC_URL/api/version" >/dev/null 2>&1 || CCC_URL="http://127.0.0.1:8090"
curl -sf --max-time 2 "$CCC_URL/api/version" >/dev/null 2>&1 || CCC_DOWN=1

Notes: (a) run every CCC curl with the network sandbox disabled — the Bash sandbox blocks loopback and fails spuriously even when CCC is up. (b) URL-encode repo_path in query strings (+ → %2B, space → %20). (c) Resolve your own session id from $CLAUDE_SESSION_ID, else the newest *.jsonl under ~/.claude/projects/<slugified-cwd>/ (see ccc-orchestration).

Step 1 (you): assemble the message architecture

Before spawning anything, fix the architecture — it's shared, only the voice varies, and that's what makes the comparison clean:

• AUDIENCE — who this is for.
• CLAIM — the ONE key claim.
• PROOF POINTS — real and checkable; writers may use only these.
• CTA — the single action.
• CHANNEL + LENGTH LIMIT — where it runs and how long it can be.

If the user didn't supply these, derive them from context and confirm before spawning.

Step 2: spawn writers A and B in parallel

Both with report_to set to your own session id. Omit "model" and "reasoning_effort": the server spawn defaults (Settings → Spawn defaults) apply. Pass either explicitly to keep cost down, with "engine" alongside it, since both are validated per engine (see ccc-orchestration § 2 for the per-engine effort ladders).

curl -s -X POST "$CCC_URL/api/sessions/spawn" -H "Content-Type: application/json" -d @- <<'JSON'
{
  "prompt": "Write <deliverable> for <channel>. Message architecture — do not violate it: AUDIENCE: … / CLAIM: … / PROOF POINTS: … / CTA: … / LENGTH LIMIT: …. Your voice constraint: <VOICE>. Use ONLY claims from the proof list — invent nothing. Report the draft text only, no commentary.",
  "repo_path": "/abs/path/to/repo",
  "report_to": "<your-session-id>"
}
JSON

Spawn twice, changing only <VOICE>. Example voices:

• A = "plainspoken founder: first person, concrete, zero hype words".
• B = "sharp product marketing: benefit-led, punchy, pattern-interrupt opener".

Waiting for the report(s)

After spawning the writers, end your turn and tell the user both drafts are being written. Drafts arrive by injection (the report_to footer). Never poll or sleep-loop. If a draft never arrives, check GET /api/sessions/spawned for whether that writer is still alive.

Step 3: spawn the judge

Only once both drafts have arrived, spawn the judge with both drafts inline (again report_to you):

curl -s -X POST "$CCC_URL/api/sessions/spawn" -H "Content-Type: application/json" -d @- <<'JSON'
{
  "prompt": "Score two anonymous drafts against this message architecture: <architecture>. DRAFT 1: <A text>. DRAFT 2: <B text>. Rubric, 1-5 each: claim fidelity (any invented claim = automatic fail), clarity of the first two lines, proof integration, CTA strength, voice consistency. Report: a scores table, the winner, and a steal list — what the loser did better that should be grafted onto the winner.",
  "repo_path": "/abs/path/to/repo",
  "report_to": "<your-session-id>"
}
JSON

Then end your turn again and wait for the judge's report the same way.

Output to the user

Winner draft + the judge's scores table + the steal list. Drafts only — nothing gets posted or published; publishing is a human decision.

Dry run

If the arguments contain dry-run, print the session count (writers + judge), the message architecture, each writer's voice constraint and prompt, and the target repo — then POST nothing.

When CCC is down

If CCC_DOWN=1 or a curl returns connection refused (exit 7): do not pretend it ran. Fall back to two Task-tool subagents for the writers and one for the judge — same independence, less visibility — and tell the user CCC was unreachable.

What this is not

Not asking one session for "two versions" — same voice DNA, so they converge and you learn nothing. The independence of separately-spawned writers is the product. Not press-room (that fans ONE release out to many channels; this compares TWO voices on ONE piece).